318 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
intestine with one main loop; pectoral fins reaching a little past pelvic 
insertions and pelvics almost to anal origin; depressed dorsal fin 
reaches to front edge of third scale in front of adipose origin. 
In the male the middle two-thirds of the first 10 to 12 branched 
anal rays have small retrorse hooks, those on the first five rays en- 
larged; rays of lower lobe of caudal fin of males with retrorse hooks. 
The dermal sac on base of lower caudal fin lobe is shown for the 
holotype in figure 41, c. 
Coloration.—In alcohol this species is pale, with a black caudal 
spot that occurs about equally on caudal peduncle and on midbase 
of caudal fin, posteriorly this spot ending in a blunt point and not 
extending out on the middle caudal fin rays; midaxis of body poste- 
riorly with a narrow silvery streak, or a series of more or less embedded 
black pigment cells; base of anal rays outlined with black pigment; 
along the back the margins of the scale pockets with black pigment; 
above base of anal fin are 2 or 3 irregular rows of black pigment cells 
rather widely separated from each other; dorsal surface of head, tip 
of snout, and front of lower jaw rather heavily black pigmented; tips 
of second to fourth or fifth branched rays of dorsal fin with black 
pigment, tips of first to fourth branched anal rays with black pigment. 
The following color notes were recorded for this species when it 
was taken out of the Rio San Pedro on March 20, 1942: Base of each 
lobe of caudal fin bright red above and below black caudal spot; 
upper part of eye bright red. | 
Remarks.—This new species differs from the only other species 
referred to the genus Saccoderma as indicated in the following key: « 
la. Black pigment at tips of first to fourth or fifth branched rays of dorsal and 
anal fins; caudal spot bluntly rounded posteriorly when caudal fin is fully 
spread, and ending abruptly and not continuing halfway out to tips of 
middle rays; pelvic insertion equidistant between snout tip and base of 
last anal ray to half a snout length behind anal base. 
Saccoderma melanostigma, new species 
1b. Black pigment cells evenly distributed on outer third of nearly all branched 
rays of dorsal and anal fins; caudal spot ending in a blunt point about 
halfway out on middle caudal fin rays; pelvic insertions equidistant 
between tip of snout and a snout length behind base of anal fin. 
Saccoderma hastata (Higenmann) 
Named melanostigma in reference to the black caudal spot. 
Genus ODONTOSTILBE Cope 
Odontostilbe Corr, Proc. Amer. Philos. Soc., vol. 11, p. 566, fig. 4, 1870. (Type, 
Odontostilbe fugitiva Cope.) 
ODONTOSTILBE PULCHER (Gill) 
Poecilurichthys pulcher Giuu, Ann. Lye. Nat. Hist. New York, vol. €, p. 59, 1858 
(Trinidad). 
Chirodon (Odontostilbe) pulcher Lirxen, Vid. Medd. Naturh. Foren. Kj¢benhavn, 
Nos. 12-16, p. 238, 1874 (locality ? [Venezuela]). 
